By Hydrosimulatics INC  

Michigan and the other Great Lakes states and provinces have each enacted laws that regulate water uses within the Great Lakes Basin.  The laws are in accordance with the Great Lakes-St.Lawrence River Basin Water Resources Compact and a parallel international Agreement to manage the groundwater and surface water resources within the Great Lakes Basin, and to prohibit diversions outside the Basin.  The Water Use Program is responsible for registering large quantity withdrawals, collecting annual water use data, making determinations on the potential impacts to water resources as a result of proposed withdrawals, and processing water withdrawal permits.  The information managed by the Water Use Program provides an environmental baseline for managing water resources in an integrated manner and strengthens the legal basis for opposing unwarranted diversions of Great Lakes water.

Use MAGNET to perform an evaluation of the following situation:

A well located 5000 ft from a stream which is connected to the aquifer discharges 500 gpm. The transmissivity of the aquifer is 105  ft2t/day, and the specific yield is 0.25. If pumping from the well is to be regulated so that the rate of withdrawal from the stream is less than 50% of the well discharge, how long may the well be pumped?

MAGNET/Modeling Hints: 

  • Use 'Synthetic Mode' to set up your flow model ( 'Other Tools' > 'Utilities' > 'Go to Synthetic Case Area')
  • Use the ‘Distance Display’ capabilities when editing geometric features and/or the ‘Ruler’ tool to properly represent distances between model features.
  • Represent the stream using a zone feature. 
  • Assume an aquifer thicknnes and compute hydraulic conductivty given the transmissivity.